Image forming apparatus having automatic paper feeding cassette installing device

ABSTRACT

An image forming apparatus including a main part having an inputting part, an image forming part to form an image on a printing paper, and a pickup roller to supply the printing paper to the image forming part, the image forming apparatus further including a paper feeding cassette to move inside and outside of the main body and to load the paper to the pickup roller, a paper feeding cassette installing unit to move the paper feeding cassette inside and outside the main body, and a controlling part to control the paper feeding cassette installing unit according to an electrical signal applied through the inputting part to load the paper to the pickup roller.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(a) from Korean Patent Application No. 2005-0074808, filed on Aug. 16, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present general inventive concept relates to an image forming apparatus, and more particularly, to an image forming apparatus having a paper feeding cassette installing device to automatically install a paper feeding cassette.

2. Description of the Related Art

Generally, an image forming apparatus is connected to a computer to form an image on paper by ink or toner according to an output signal corresponding to image data generated at the computer. According to an image forming method and function, the image forming apparatus may be classified as an inkjet printer, a laser beam printer, a scanner, a fax, or a multi-function printer having all the foregoing functions.

Recently, an image forming apparatus that may be directly connected to a portable host apparatus to communicate image data therebetween without the intermediation of the computer has been developed. The portable host apparatus may be a PDA (personal digital assistant), a digital camera, a camcorder, a cellular phone, a memory stick, and the like.

Particularly, as a photographing technology of image data in the digital camera or the cellular phone has been developed and widely used, the photo image data taken by a user with the digital camera or the cellular phone is directly printed out through the image forming apparatus, which leads to a compact image forming apparatus exclusively used for photo image data.

According to a conventional image forming apparatus for photo image data as illustrated in FIG. 1, a paper feeding cassette 10, which is separately provided to a main body (not illustrated) of the image forming apparatus, is installed to the main body of the image forming apparatus to print image data. The paper feeding cassette 10 comprises a cover 11 and a paper loading part 13. The cover 11 is coupled to the paper loading part 13 by a hinge 15 to cover and uncover the paper loading part 13.

However, according to the conventional paper feeding cassette 10, when predetermined image data is printed on paper, the paper feeding cassette 10 for a size of the paper corresponding to the image data needs to be installed to the main body of the image forming apparatus. Therefore, different sizes of paper feeding cassettes 10 are required to print image data on paper having different sizes. For example, when image data having the size of a postcard is printed, the paper feeding cassette for the size of a postcard needs to be installed to the main body of the image forming apparatus, whereas when image data having the size of 4×6 inches, the paper feeding cassette should be replaced with the paper feeding cassette for paper having a corresponding size loaded.

Also, as the conventional paper feeding cassette 10 is provided separately from the main body of the image forming apparatus, it is repeatedly installed to and removed from the main body for individual image forming, and as the different sizes of paper feeding cassettes 10 should be provided to a main body of the image forming apparatus, the space occupied by the image forming apparatus should become large and the portability of the image forming apparatus is deteriorated.

SUMMARY OF THE INVENTION

The present general inventive concept provides an image forming apparatus having a paper feeding cassette that is automatically installed to a main body according to a loaded printing paper with high portability.

Additional aspects and/or advantages of the present general inventive concept will be set forth in part in the description which follows, and in part, will be obvious from the description, or may be learned by practice of the present general inventive concept.

The foregoing and/or other aspects and utilities of the present general inventive concept may be achieved by providing an image forming apparatus comprising a main body comprising an inputting part, an image forming part to form an image on a printing paper, and a pickup roller to supply the printing paper to the image forming part, a paper feeding cassette to move inside and outside of the main body to load the paper to the pickup roller, a paper feeding cassette installing unit to move the paper feeding cassette inside and outside of the main body, and a controlling part to cotnrol the paper feeding cassette installing unit according to an electrical signal applied through the inputting part to load the paper to the pickup roller.

The paper feeding cassette installing may comprise a driving part located at a side of the main body, a driven part located at the paper feeding cassette to correspond to the driving part to move the paper feeding cassette inside and outside of the main body, and a power supplying part controlled by the controlling part to supply electric power to the driving part.

The driving part may comprise a gear, and the driven part may comprise a rack.

The driving part may comprise a belt and a pulley, and the driven part may comprise a rack.

The paper feeding cassette installing unit may further comprise a paper sensing part to detect the printing paper loaded in the paper feeding cassette and to apply a sensing signal to the controlling part, and the controlling part controls the power supplying part to supply the electric power to the driving part according to the sensing signal.

The paper feeding cassette may further comprise an elastic member to elastically press the printing paper against the pickup roller according to an amount of the printing paper loaded on the paper feeding cassette to load the printing paper to the pickup roller.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a feeding cassette useable with an image forming apparatus, including at least one adjustable size guide to accommodate a plurality of sizes of printing media, a detecting unit to detect the presence or absence of the printing media in the feeding cassette, and a guide unit to guide the feeding cassette into the image forming apparatus.

The detecting unit may include a contact switch to detect the presence or absence of the printing media in the feeding cassette. The detecting unit may include a pressure sensor to detect an amount of the print medium in the feeding cassette.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing an image forming apparatus, including a frame, a feeding cassette automatically-moveable into and out of the frame, the feeding cassette including at least one adjustable size guide to accommodate a plurality of sizes of printing media, and a controller to control a movement of the feeding cassette into and out of the frame.

The frame may include a first guide unit to receive the feeding cassette, and the feeding cassette may include a second guide unit to engage with the first guide unit. The image forming apparatus may further include an input unit to receive an input command from a user to control a movement of the feeding cassette into and out of the frame and to transmit the input command to the controller, and the controller may control a movement of the feeding cassette into and out of the frame based on the input command. The image forming apparatus may further include a detecting unit to detect the presence or absence of the printing media in the feeding cassette and to transmit a command to the controller based on the detection result, and the controller may control a movement of the feeding cassette into and out of the frame based on the command. The detecting unit may include a contact switch to detect the presence or absence of the printing media in the feeding cassette and to transmit a command to the controller based on the detection result, and the controller may control a movement of the feeding cassette into and out of the frame based on the command. The detecting unit may include a pressure sensor to detect an amount of the printing media in the feeding cassette and to transmit a command to the controller based on the detection result, and the controller may control a movement of the feeding cassette into and out of the frame based on the command. The image forming apparatus may further include at least one retaining unit to prevent the feeding cassette from being entirely removed from the frame. The frame may include the at least one retaining unit. The feeding cassette may include the at least one retaining unit. The image forming apparatus may further include a plurality of retaining units, wherein the frame and the feeding cassette each include at least one retaining unit of the plurality of retaining units.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a method of automatically moving a feeding cassette into and/or out of an image forming apparatus, the method including determining whether a printing medium is present in the feeding cassette using the detecting unit when the feeding cassette is in the image forming apparatus, sending an out command signal from the detecting unit to the controller to move the feeding cassette out of the image forming apparatus when the printing medium is not present in the feeding cassette, and moving the feeding cassette out of the image forming apparatus using the controller based on the out command signal.

The method may further include determining whether a printing medium is present in the feeding cassette using the detecting unit when the feeding cassette is out of the image forming apparatus, sending an in command signal from the detecting unit to the controller to move the feeding cassette into the image forming apparatus when the printing medium is present in the feeding cassette, and moving the feeding cassette into the image forming apparatus using the controller based on the in command signal. The detection unit may include a contact sensor. The detection unit may include a pressure sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a perspective view illustrating a conventional paper feeding cassette.

FIG. 2 is a perspective view illustrating an image forming apparatus according to an embodiment of the present general inventive concept.

FIG. 3 is a block diagram illustrating an image forming apparatus of according to an embodiment of the present general inventive concept.

FIG. 4 is a side view illustrating a paper feeding cassette installing device of an image forming apparatus according to an embodiment of the present general inventive concept.

FIG. 5 is a side sectional view illustrating an operation of an image forming apparatus according to the present general inventive concept.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.

FIG. 2 is a perspective view illustrating an image forming apparatus according to an embodiment of the present general inventive concept, and FIG. 3 is a block diagram illustrating and image forming apparatus according to an embodiment of the present general inventive concept.

As illustrated in FIGS. 2 and 3, an image forming apparatus 1 according to an embodiment of the present general inventive concept comprises a main body 100, a paper feeding cassette 200 to move inside and outside of the main body 100, a paper feeding cassette installing device 300 to automatically move the paper feeding cassette 200 inside and outside the main body 100, and a controlling part 600 to control the above parts.

The main body 100 comprises an inputting part 120 to receive a signal from a user, a displaying part 130 to display a signal input through the inputting part 120 and an operating state of the image forming apparatus 1 corresponding to the input signal, an image forming part 700 to form an image on a printing paper, and a casing 110 to accomodate the above parts.

The inputting part 120 comprises an operating panel (not illustrated) provided on an outer surface of the casing 110 to receive a printing signal and a paper feeding cassette moving signal from the user.

The image forming part 700 may be of an inkjet type (where an image is formed on the printing paper when an ink cartridge containing ink jets the ink during reciprocation of the ink cartridge), of a laser beam type (where an image is formed on the printing paper by toner applied by a potential difference between a photosensitive element and a developing roller), or of a thermal type (where ink on an ink ribbon is coated on the printing paper by heating and pressing the ink ribbon onto the printing paper with a thermal printhead (TPH)).

The paper feeding cassette 200 is provided to move inside and outside of the main body 100, and comprises a paper loading plate 210 to load the printing paper, a paper guide 240 to keep the printing paper loaded on the paper loading plate 210 in place, an elastic member 220 to press the loaded printing paper toward a pickup roller 800 (see FIG. 5), and a paper sensing part 500 to detect a remaining amount of the loaded printing paper.

The paper guide 240 may be provided as a pair of paper guides 240 located at opposite sides of the paper loading plate 210 to prevent the printing paper loaded on the paper loading plate 210 from shifting. Furthermore, the paper guide 240 may be movable to effectively guide printing papers of variable sizes. The paper guide 240 may be moved by conventionally known moving mechanisms.

The elastic member 220 may be provided to protrude from the paper loading plate 210 through a hole 230 in the paper loading plate 210 to elastically press the printing paper loaded thereon upwardly, so that the printing paper may be loaded to the pickup roller 800, which supplies the printing paper to the image forming part 700. Accordingly, the paper may be easily picked up by the pickup roller 800, and the driving force needed to pick up the printing paper may be reduced.

The elastic member 220 may comprise a plate spring or a coil spring, and may be designed to have a suitable modulus of elasticity according to an amount of the loaded printing paper.

The paper sensing part 500 may be provided on the paper loading plate 210 of the paper feeding cassette 200 to detect the amount of the loaded printing paper. The paper sensing part 500 may comprise a pressure sensor that senses the amount of the loaded printing paper based on a weight of the loaded printing paper. In addition, the paper sensing part 500 may comprise a contact switch that senses only the presence of the paper by contacting the printing paper. However, the paper sensing part 500 is not limited to being a pressure sensor or a contact switch. The paper sensing part 500 transmits a sensing signal based on the amount of the paper or the presence of the paper to the controlling part 600.

The paper feeding cassette installing device 300 automatically moves the paper feeding cassette 200 inside and outside of the main body 100 according to the input signal input by the user through the inputting part 110 and according to the sensing signal corresponding to the amount of or the presence of the printing paper detected by the paper sensing part 500. That is, when the paper sensing part 500 transmits the sensing signal that has information that there is no printing paper loaded on the paper feeding cassette 200, the paper feeding cassette installing device 300 automatically moves the paper feeding cassette 200 outside of the main body to inform the user of the need of additional paper. If the user supplies the printing paper in the paper feeding cassette 200, the paper feeding cassette installing device 300 automatically installs the paper feeding cassette 200 inside the main body 100.

Also, if the user inputs a paper supply signal through the inputting part 110 irrespective of the presence of the paper in the paper feeding cassette 200, the paper feeding cassette installing device 300 automatically withdraws the paper feeding cassette 200 from the main body 100.

As illustrated in FIG. 2, the paper feeding cassette installing device 300 according to the present embodiment may comprise a gear 310 provided in the main body 100, a rack 320 provided in the paper feeding cassette 200 to engage with the gear 310, and a power supplying part 330 to supply electric power to the gear 310.

The power supplying part 300 supplies the electric power to the gear 320 when it receives the power supply signal from the controlling part 600, and cuts off the electric power supplied to the gear 320 when it receives a power supply stop signal from the controlling part 600, or when it no longer receives the power supply signal from the controlling part 600.

The gear 320 rotates when it receives the electric power from the power supplying part 300, thus moving the paper feeding cassette 200 outside of the main body 100 using the rack 310 engaged with the gear 320. The gear 320 may be at an outermost side part of the main body 100 to move outside the paper feeding cassette 200 as far as possible from the main body 100. Also, the gear 320 and the rack 310 may have teeth of a small size and a small pitch to precisely control a position of the paper feeding cassette 200.

When the paper feeding cassette 200 being positioned outside of the main body 100 is supplied with the printing paper, the gear may rotate in the opposite direction so that the paper feeding cassette 200 may move inside of the main body 100.

The image forming apparatus 1 and/or the paper feeding cassette 200 may include at least one retaining unit to prevent the paper feeding cassette 200 from being entirely removed from the image forming apparatus 1 when the paper feeding cassette 200 is moved outside of the image forming apparatus 1. In other words, the image forming apparatus 1 and/or the paper feeding cassette 200 may include at least one retaining unit such that the paper feeding cassette 200 is moved outside of the image forming apparatus 1 to a distance allowing the input of a print medium into the paper feeding cassette 200; however, the at least one retaining unit prevents the paper feeding cassette 200 from being completely removed from the image forming apparatus 1.

An operation of the image forming apparatus 1 according to and embodiment of the present general inventive concept will now be described with reference to FIGS. 2, 3 and 5.

A user electrically connects a host apparatus (not illustrated) to a host apparatus connecting part (not illustrated) provided on the main body 100, and inputs a print signal through the inputting part 120.

When receiving the print signal, the controlling part 600 determines if printing paper P is present in the paper feeding cassette 200 using the paper sensing part 500. The paper sensing part 500 detects the presence of the printing paper P by, for example, a weight of the printing paper P loaded in the paper loading part 200 or through contact with the printing paper P, and transmits a sensing signal to the controlling part 600.

If there is no printing paper P in the paper loading part 200, the controlling part 600 receives a signal informing “no printing paper” from the paper sensing part 500 and controls the power supplying part 330 to supply electric power to the gear 320. The gear 320 rotates when it is supplied with the electric power, and the rack 310 engaged with the gear 320 moves according to the rotation of the gear 320, so that the paper feeding cassette 200 moves outside of the main body 100.

Due to the combination of the rack 310 and the gear 320, the paper feeding cassette 200 moves outside of the main body 100, and the user is informed that there is no printing paper P in the paper feeding cassette 200, so that the user can supply additional paper P into the paper feeding cassette 200.

Then, the paper sensing part 500 informs the controlling part 600 that the printing paper P is present in the paper feeding cassette 200. The controlling part 600 controls the power supplying part to supply electric power to the gear 320, and the gear 320 rotates in the opposite direction, so that the paper feeding cassette 200 moves inside the main body 100.

Meanwhile, when the user supplies the printing paper P in the paper feeding cassette 200, the user positions the printing paper P at the center of the paper loading plate 210, and fixes the position of the printing paper P by adjusting the paper guide 240 to prevent the printing paper P from shifting on the paper loading plate 210. The paper P is then pressed upwardly by the elastic member 220 provided on the paper loading plate 210 to contact the pickup roller 711.

As illustrated in FIG. 5, when the paper feeding cassette 200 moves inside the main body 100, the paper P is automatically loaded to the pickup roller 711 and is moved to the image forming part 700 along a paper feeding path.

According to the paper supply signal input by the user through the inputting part 120, the paper feeding cassette 200 operates in the same way as described above.

As illustrated in FIG. 4, a paper feeding cassette installing device 400 according to an embodiment of the present general inventive concept may comprise a toothed pulley 410 provided inside of the main body 100, a driven pulley 420 driven by the toothed pulley 410, a toothed belt 430 to engage with the toothed pulley 410 and the driven pulley 420, and a rack 440 provided at opposite sides of the paper feeding cassette 200 and to engage with the toothed belt 430.

The toothed pulley 410 rotates when the power supplying part 330 supplies electric power to the toothed pulley 410 of the main body 100. The toothed belt 430, which is engaged with the toothed pulley 410, then rotates, which also rotates the driven pulley 420. As the rack 440 provided at the paper feeding cassette 200 is engaged with the toothed belt 430, the rack 440 moves outside of the main body 100 according to the rotation of the toothed belt 430.

If a printing paper is supplied to the paper feeding cassette 200 that has moved outside of the main body 100, the toothed pulley 410 rotates in the opposite direction so that the paper feeding cassette 200 moves inside of the main body 100.

The controlling part 600 controls the power supplying part 300 to move the paper feeding cassette 200 outside of the main body 100 when it receives a paper supply signal through the inputting part 120 by the user or a signal that contains information that there is no printing paper loaded in the paper feeding cassette 200 from the paper sensing part 500.

That is, if there is no printing paper in the paper feeding cassette 200 or if the user inputs the paper supply signal, the controlling part 600 controls the power supplying part 330 to supply electric power to the toothed pulley 410 so that the paper feeding cassette 200 may be moved outside of the main body 100. The user is informed that the printing paper needs to be loaded in the paper feeding cassette 200 by the moved paper feeding cassette 200. If the printing paper is loaded in the paper feeding cassette 200 by the user, the toothed pulley 410 is supplied with the electric power and rotates in the opposite direction so that the paper feeding cassette 200 may be installed to the main body 100.

As described above, the image forming apparatus according to various embodiments of the present general inventive concept comprises a paper feeding cassette that automatically moves inside and outside of a main body of the image forming apparatus, thereby eliminating the inconvenience of manually installing a paper feeding tray.

Also, according to various embodiments of the present general inventive concept, as a paper feeding cassette is accommodated inside of a main body of an image forming apparatus, space occupied by the image forming apparatus is reduced, and a volume of the main body becomes compact. Accordingly, portability of the image forming apparatus is enhanced.

Also, according to various embodiments of the present general inventive concept, as a paper feeding cassette comprises a paper guide to support printing papers of variable sizes, conventional paper feeding cassettes of different sizes are not needed.

Also, according to various embodiments of the present general inventive concept, as a paper feeding cassette automatically moves outside of a main body of the image forming apparatus to inform a user of a need of a paper supply when there is no printing paper in the paper feeding cassette, a convenience in use is enhanced.

Also, according to various embodiments of the present general inventive concept, as paper is loaded to a position of a pickup roller by an elastic member when a paper feeding cassette is installed into a main body of an image forming apparatus, a driving force required to pick up the paper is decreased.

Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents. 

1. An image forming apparatus, comprising: a main body comprising: an inputting part, an image forming part to form an image on a printing paper, and a pickup roller to supply the printing paper to the image forming part; a paper feeding cassette to move inside and outside of the main body and to load the paper to the pickup roller; a paper feeding cassette installing unit to move the paper feeding cassette inside and outside of the main body; and a controlling part to control the paper feeding cassette installing unit according to an electrical signal applied through the inputting part to load the paper to the pickup roller.
 2. The image forming apparatus according to claim 1, wherein the paper feeding cassette installing unit comprises: a driving part located at a side of the main body; a driven part located at the paper feeding cassette to correspond to the driving part and to move the paper feeding cassette inside and outside of the main body; and a power supplying part controlled by the controlling part to supply electric power to the driving part.
 3. The image forming apparatus according to claim 2, wherein: the driving part comprises a gear; and the driven part comprises a rack.
 4. The image forming apparatus according to claim 2, wherein: the driving part comprises a belt and a pulley; and the driven part comprises a rack.
 5. The image forming apparatus according to claim 2, wherein: the paper feeding cassette installing unit further comprises a paper sensing part to detect the printing paper loaded in the paper feeding cassette and to apply a sensing signal to the controlling part, and the controlling part controls the power supplying part to supply the electric power to the driving part according to the sensing signal.
 6. The image forming apparatus according to claim 1, wherein the paper feeding cassette further comprises an elastic member to elastically press the printing paper against the pickup roller according to an amount of the printing paper loaded on the paper feeding cassette to load the printing paper to the pickup roller.
 7. A feeding cassette useable with an image forming apparatus, comprising: at least one adjustable size guide to accommodate a plurality of sizes of printing media; a detecting unit to detect the presence or absence of the printing media in the feeding cassette; and a guide unit to guide the feeding cassette into the image forming apparatus.
 8. An image forming apparatus, comprising: a frame; a feeding cassette automatically-moveable into and out of the frame, the feeding cassette including at least one adjustable size guide to accommodate a plurality of sizes of printing media; and a controller to control a movement of the feeding cassette into and out of the frame.
 9. The image forming apparatus of claim 8, wherein: the frame includes a first guide unit to receive the feeding cassette; and the feeding cassette includes a second guide unit to engage with the first guide unit.
 10. The image forming apparatus of claim 8, further comprising: an input unit to receive an input command from a user to control a movement of the feeding cassette into and out of the frame and to transmit the input command to the controller, wherein the controller controls a movement of the feeding cassette into and out of the frame based on the input command.
 11. The image forming apparatus of claim 8, further comprising: a detecting unit to detect the presence or absence of the printing media in the feeding cassette and to transmit a command to the controller based on the detection result, wherein the controller controls a movement of the feeding cassette into and out of the frame based on the command.
 12. The image forming apparatus of claim 11, wherein the detecting unit comprises a contact switch to detect the presence or absence of the printing media in the feeding cassette and to transmit a command to the controller based on the detection result, wherein the controller controls a movement of the feeding cassette into and out of the frame based on the command.
 13. The image forming apparatus of claim 11, wherein the detecting unit comprises a pressure sensor to detect an amount of the printing media in the feeding cassette and to transmit a command to the controller based on the detection result, wherein the controller controls a movement of the feeding cassette into and out of the frame based on the command.
 14. The image forming apparatus of claim 8, further comprising at least one retaining unit to prevent the feeding cassette from being entirely removed from the frame.
 15. A method of automatically moving a feeding cassette into and/or out of an image forming apparatus, the method comprising: determining whether a printing medium is present in the feeding cassette using the detecting unit when the feeding cassette is in the image forming apparatus; sending an out command signal from the detecting unit to the controller to move the feeding cassette out of the image forming apparatus when the printing medium is not present in the feeding cassette; and moving the feeding cassette out of the image forming apparatus using the controller based on the out command signal. 